With today's proliferation of communication systems, compatible communication devices are also becoming more prevalent, as well as advanced. Examples of communication devices include both handheld communication devices as well as larger devices such as laptop computers, desktop computers and the like. These devices are capable of sending and receiving a variety of different messages including, but not limited to, short message service (SMS), multimedia message service (MMS), emails, voice messages, and the like.
Often these communication devices are equipped with physical keyboards. One benefit of a physical keyboard is that it typically provides the user tactile feedback. The tactile feedback from the keyboard can be achieved in a variety of ways including the use of one or more dome switches that are typically incorporated, one each, with depressible “keys” of the keyboard. The structure of the dome switch is collapsible.
While tactile feedback benefits the user in entering text, the average user must primarily rely on his/her sense of vision to confirm the accuracy in typing. Therefore, one process known in the art is to utilize a lighting source to shine through, upon, or around an intended group of keys so that the lit keys may be better recognized by the user. Such lighting is especially helpful when using the handheld communication device in a dark environment with reduced visibility. But the lighting source must be controlled so that it only highlights the appropriate keys. A user may be confused if light seeps from the lighting source such that in addition to highlighting a designated key, the light erroneously highlights an undesignated key. For example, if the user is using the phone-function on a handheld communication device with a reduced alphanumeric keyboard, the user would likely prefer that only those keys possessing numeric characters be highlighted. However, should other keys be erroneously highlighted as well, ones that are not used in connection with the phone function, the user may confuse some of the erroneously highlighted keys as intended for the phone function. Therefore, since the lighting source is intended to benefit the user by distinguishing those keys that are appropriate for a particular function (i.e. numeric keys for telephone functionality), it is important that the lighting source not inadvertently seep and highlight inappropriate keys.
As mentioned hereinabove, providing a keypad which provides both tactile feedback and utilizes a lightsource to provide further visual feedback is beneficial to the user of a handheld communication device. However, a current problem in the art makes it difficult to accomplish both functions on the same device. Specifically, to acquire better tactile feedback in a keypad, a small interference, between approximately 0.1 and 0.15 mm, must be added to the key's actuator and dome. However, in adding this interference, the increased height of the actuator and dome, when fully assembled, may apply pressure against the light-restricting film used to direct the light emitted from a lightsource. As a result, the light, no longer being optimally restricted, may seep and erroneously highlight other keys. Thus it is desirable to control the light's distribution to the keyboard and also reduce or eliminate unintended light “leaks” or emissions while retaining the desired tactile feedback associated with a physical keyboard.